Turbine.



B. LJUNGSTRDM. I

TURBINE.

APPLICATION FILED PIE-13.23

\ Patented Dec.. 8, 19018.

I llll Inventor.

BIRGER LJUNGSTROM, OF STOGKHOLM, SWEDEN.

TURBIN Specification of Letters Patent.

Patented Dec. 8, 1908.

Application filed. February 23, 1907. Serial No. 358,963.

To all whom it may concern."

Be it known that I, BIRGER LJUNGsTRoM, a subject of the King of Sweden, residing at 8 Flemminggatan, Stockholm, Sweden, have invented certain new and useful Improvements in Gas-Turbines; and I do herebydeclare the following to be a full} clear, and exact description of, the invention, such as. will enable others skilled in the art to which it appertains to make and use the same, ref. erence being had to the accompanying drawings, and to'letters or figures of reference marked thereon, which form a partof this specification. J

This inven bines and is designed to render them more compact in order not only to diminish the leakage but also to make-it possible to manufacture turbines of great speed.

In the accompanyin drawings Figure 1 is a vertical longitudina section of a radial turbine. compound or dual stage radial turbine.

Fig. 3 is a part of the vane rings in vertical transverse section.

Fig, 4 is a vertical 'sec tion of a vane ring, and Fig. 5 illustrates a modified form.

ln order to attain the fullest and most economical expansion of the fluid it is necessary with these turbines that the fluid passes through a large number of cylindrical vane-rings placed outside of or threaded into each other and divided alternately into' two series rotating relatively to each other.

- Such turbines offer, theoretically, important which may be iven" them without causing too great centril ugal strains. With the systoms of construction now used,'especially with high expansion of the elastic fluid and large circuit areas, the vanes mustbe constructed of comparatively great width, that is to say, they occupy alarge space in a radial direction. A radial flow turbine constructed with such vanes must necessarily be of lar e diameter and slow speed, as owing to con i-' tions of strength a certain peripheral speed must not be exceeded. This not only rende'rs the turbine much more ex ensive butplsp increases the cost. of the ynamo driven tion relates to radial fiowtur- Fig. 2is a longitudinal section of a thereby when such is used. These drawbacks are, however, notthe only ones nor perhaps even the most important. Owing to the large diameter required the length of the leakage; slots past the vane-edges and packing-rings is mcreased'in the same proportion the consequence being that the leak age. is still further increased on account of the large free space which is required by the large dimensions and necessitated by their greater change of form on being heated. This loss byleakage has proved to be part-iced larly prejudicial in turbines of small power.

In order to overcome these disadvantages it has for example been constructed as a radial flow turbine composed of several radial turbines of medium diameter placed axially behind each other, through which the steam -must pass 1n series in order to attain the necessary expansion. Besides great complexity further losses arise on transferring the fluid from one turbine to the other. These latter losses as well as those due to leakage indicated in connection with the sin is radial flow turbine may be avoided wit out dividing the turbine into several turbines, if vanes of sufficient strength are constructed. with such small radial extension, --that the necessary; number of vanes can be accommodated in a single radial flow turbine of small diameter.

The present invention comprises a method of constructing such vane series enabling the use of single, radial turbines of great efliciency and small diameter, even with high power and with great decrease of volume, weight and cost of manufacture. It is obvious for instance in the case of radial marine turbines where the number of revolutions for various reasons must be very low, that great advantages with regard to diameter, weight and cost may be attained by such vane-series. even when a division of the turbine into high-pressure and lowpressure turbines on the same or on different propeller shafts must be resorted to.

As shown in Figs. 3, 4 and 5 of the annexed drawing according to the present invention the vane-rings are not divided but are formed as complete rings with the vanes divided into two or more lengths with the cross section bent in, the same direction, and supported by intermediate complete carrier or fastening rings, which are formed in one continuous piece with the vane ends or otherwise firmly connected thereto and therefore need not roject outside or inside the inner or outer e ge of the vanes. In this manner durable vane disks or drums are constructed having a very slight radial exl tension and at the same time small diameter and large circuit-area is obtained.

In connection herewith it may be pointed out, that the inventor is aware that turbines have been previously constructed with vanerings placed in alinement and provided with concentric fastenings. This arrangement however has no reducing efiect on the diameter as the latter may in such an arran ement be chosen according to the length of t 1e turbine as desired. This reduction of diameter and consequent decrease in losses due to leakage or transfer which as above said are obtained by applying the said arrangement to radial flow turbines, therefore comprises that new technical eliect which is aimed at by the present invention and which is not obtained by the above named arrangement. Centrifugal strains in the vanes of an axial turbine may in addition be taken up by the connections or fastenings alone and need not,

as in the case of radial turbines, cause bendlng strains and consequent division into several lengths with lnterposed strengthening rings.

On Fig. 1 the stationary vanes 5 and the rotating vanes 6 consist of perforated cyl= inders constructed as aforesaid and threaded into each other. D

Fig. 2 shows a marine turbine with two expansion chambers, constructed according to the same princi le, wherein, as in Fi 1 the stationary and the rotating vane-cy inders 15 and 16 respectively are fastened to fiat or plane disks. The stationary cylinders 15 are notplaced directly on the turbine casing but on separate or independent plates 17.

In Figs. 3 and 4 the-vanes 1 and ring are made in one piece while in Fig. 5, I have shown four separate vane rings 2 each having a separate series of vanes 1 These rings 2*" are angular in cross section so that when several rings are assembled their flanges interlock and form a composite stiii vane-ring.

I claim:

1. In a radial turbine vanes united in rings, said vanes being divided in lengths by means of rings intermediate the vane ends.

2. In a radial turbine vanes united in rings, said vanes being divided in lengths by means of carrying rings intermediate the vane ends, said rings being rigidly secured to said vanes.

3. In a radial turbine vanes united in rings, said vanes being divided in lengths by means of rings. intermediate the vane ends, said ends being connected to each other.

4. In a radial turbine vanes united in rings, said vanes being divided in lengtlis by means of rings intermediate the vane ends, said ends being connected to each other by means of rings.

In testimony, that I claim the foregoing as my invention, and have signed my name in presence of two subscribing witnesses BIRGER LJUNGSTROM. Witnesses:

CARL FRIBERG, E. RFLBERG. 

